Chemotaxis is the process by which bacteria swim to higher concentrations of attractants or lower concentrations of repellents. Peritrichous bacteria alternately swim smoothly and tumble, whose effect is random reorientation for the next swim. Chemotaxis occurs by increasing propensity to tumble when bacteria are headed in the "unfavorable" direction and by increasing propensity to swim when the bacteria are headed in the "favorable" direction (such as toward higher attractant concentrations). We are chiefly interested in elucidating the biochemical events that underlie chemotaxis in Bacillus subtilis, and isolating and studying the factors involved. We shall be studying methylated proteins connected with chemotaxis, especially those methylated by pure methyltransferase, the enzyme that allows B. subtilis to adapt to addition of attractants. We shall attempt to identify a demethylase that removes methyl groups from certain membrane proteins upon loss of attractant. Finally, we shall be cloning chemotaxis genes in B. subtilis using an indigenous plasmid and also temperature phage in order to carry out complementation of genetic mutants previously isolated and mapped, and also to obtain radioactivity labelled chemotaxis-related proteins for their identification, purification, and study.